A typical image forming apparatus connected to a network, such as a multifunction peripheral (MFP), a printer, or the like, can be accessed from a variety of computing devices, such as cellular phones, smart phones, or mobile terminals.
A typical registration method involves a domain manager permitting an external apparatus to operate as a member of an authorized domain—such as a home network—and registering the external apparatus. However, the typical registration method requires a user authentication apparatus to be installed, and the domain manager has to confirm whether the external apparatus is permitted to operate as a member of the authorized domain and whether the external apparatus is registered by using the user authentication apparatus, resulting in a complicated operation of registering the external apparatus.